This is an interesting question. I think it really depends on the person and their own personal scale of pain. I've never broken a bone or sprained one. Nor have I cut any part of me severely enough to require stitches. I've never had surgery on anything, either. Any pain I've had rarely makes me cry (as in, "holy crap I just need this to stop").
Taking all this into account, I've got two possibilities. The first one is a gallbladder attack. It's a sharp, stabbing pain under my right breast that just never lets up. Until I take a Vicodin, the pain won't ease. My first attack ever, lasted over 6 hours as I waited for treatment in an ER. Luckily, it's a fairly rare occurrence (about once every 4-5 months) and Vicodin controls it, which is why I refuse to get it taken out.
The second possibility is an IBS attack. I've had a couple of extremely severe attacks that are enough to make me sweat and feel faint. I swear my insides are being ripped apart. And then I feel so nasty and drained afterwards that I can barely function in a decent way. I used to get IBS attacks all the time. They're mostly related to certain foods and for me, definitely stress, and they can be quite painful. But there were a couple of times where I swear I was being internally damaged on some level. It was not at all pleasant!
So, those are the only things I can think of. Feel free to share your own story in the comments!
Day 2: List 3 legitimate fears and describe how they became fears
Day 1: List 10 random facts about yourself